package com.nowcoder.community.service;


import com.github.benmanes.caffeine.cache.CacheLoader;
import com.github.benmanes.caffeine.cache.Caffeine;
import com.github.benmanes.caffeine.cache.LoadingCache;
import com.nowcoder.community.dao.DiscussPostMapper;
import com.nowcoder.community.entity.DiscussPost;
import com.nowcoder.community.util.SensitiveFilter;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.web.util.HtmlUtils;

import javax.annotation.PostConstruct;
import java.util.List;
import java.util.concurrent.TimeUnit;

/**
 * <p>Title: DiscussPostService</p>
 * <p>author 12427</p>
 *
 * @version ver1.0
 * @date 2022/7/3 9:13
 */
@Service
public class DiscussPostService {

    private static final Logger logger = LoggerFactory.getLogger(DiscussPostService.class) ;

    @Autowired
    private DiscussPostMapper discussPostMapper ;

    @Autowired
    private SensitiveFilter sensitiveFilter;


    @Value("${caffeine.posts.maxsize}")
    private int maxSize ;

    @Value("${caffeine.posts.expire-seconds}")
    private int expireSeconds ;

    // Caffeine 核心接口： cache ， loadingCache  AsynloadingCache

    // 帖子列表缓存
    private LoadingCache<String, List<DiscussPost>> postListCache ;

    // 帖子缓存总数
    private LoadingCache<Integer,Integer> postRowsCache;

    @PostConstruct
    public void init(){
        // 初始化列表缓存

        postListCache = Caffeine.newBuilder()
                .maximumSize(maxSize)
                .expireAfterWrite(expireSeconds , TimeUnit.SECONDS)
                .build(new CacheLoader<String, List<DiscussPost>>() {
                    @Nullable
                    @Override
                    public List<DiscussPost> load(@NonNull String key) throws Exception{
                        if(key == null || key.length() == 0 ) {
                            throw new IllegalArgumentException("参数错误") ;
                        }
                        String[]  params = key.split(":") ;
                        if(params == null || params.length != 2){
                            throw new IllegalArgumentException("参数错误") ;
                        }

                        int offset = Integer.valueOf(params[0]) ;
                        int limit = Integer.valueOf(params[1]) ;

                        // 二级缓存
                        // 略
                        logger.debug("load post list from db.");
                        return discussPostMapper.selectDiscussPosts(0 , offset , limit , 1 )  ;
                    }
                }) ;

        // 初始化总数缓存
        postRowsCache = Caffeine.newBuilder()
                .maximumSize(maxSize)
                .expireAfterWrite(expireSeconds , TimeUnit.SECONDS)
                .build(new CacheLoader<Integer, Integer>() {
                    @org.checkerframework.checker.nullness.qual.Nullable
                    @Override
                    public Integer load(@org.checkerframework.checker.nullness.qual.NonNull Integer key) throws Exception {
                        // 二级缓存
                        // 略
                        logger.debug("load post list from db.");
                        return discussPostMapper.selectDiscussPostRows(key)  ;
                    }
                }) ;
    }


    public List<DiscussPost> findDiscussPosts(int usereId , int offset , int limit , int orderMode) {

        if(usereId == 0 && orderMode == 1) {
            return  postListCache.get(offset + ":" + limit);
        }

        logger.debug("load post list from db.");

        return discussPostMapper.selectDiscussPosts(usereId, offset, limit , orderMode) ;
    }

    public int findDiscussPostRows(int userId) {
        if(userId == 0) {
            return postRowsCache.get(userId);
        }

        logger.debug("load post rows from db.");

        return discussPostMapper.selectDiscussPostRows(userId) ;
    }

    public int addDiscussPost(DiscussPost post){
        if(post == null){
            throw new IllegalArgumentException("参数不能为空")  ;
        }

        // 转义Html标记
        post.setTitle(HtmlUtils.htmlEscape(post.getTitle()));
        post.setContent(HtmlUtils.htmlEscape(post.getContent()));

        // 过滤敏感词
        post.setTitle(sensitiveFilter.filter(post.getTitle()));
        post.setContent(sensitiveFilter.filter(post.getContent()));

        return discussPostMapper.insertDiscussPost(post) ;
    }

    public DiscussPost findDiscussPostById(int id){
        return discussPostMapper.selectDiscussPostById(id) ;
    }

    public int updateCommentCount(int id , int commentCount){
        return discussPostMapper.updateCommentCount(id ,commentCount) ;
    }

    public int updateType(int id , int type){
        return discussPostMapper.updateType(id , type) ;
    }

    public int updateStatus(int id , int status){
        return discussPostMapper.updateStatus(id , status) ;
    }


    public int updateScore(int id , double score) {
        return discussPostMapper.updateScore(id , score) ;
    }



}
